Methods and systems for enhanced mapping of tissue

ABSTRACT

According to some embodiments, methods and systems of enhancing a map of a targeted anatomical region comprise receiving mapping data from a plurality of mapping electrodes, receiving high-resolution mapping data from a high-resolution roving electrode configured to be moved to locations between the plurality of mapping electrodes, wherein the mapping system is configured to supplement, enhance or refine a map of the targeted anatomical region or to directly create a high-resolution three-dimensional map using the processor receiving the data obtained from the plurality of mapping electrodes and from the high-resolution roving electrode.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.15/369779, filed Dec. 05, 2016, titled METHODS AND SYSTEMS FOR ENHANCEDMAPPING OF TISSUE which is a continuation of U.S. patent applicationSer. No. 15/179,891, filed Jun. 10, 2016, which is a continuationapplication of PCT/US2015/061353, filed Nov. 18, 2015, which claimspriority to U.S. Provisional Application No. 62/081,710, filed Nov. 19,2014, and U.S. Provisional Application No. 62/159,898, filed May 11,2015, the entire contents of each of which are incorporated herein byreference in their entirety.

BACKGROUND

Tissue ablation may be used to treat a variety of clinical disorders.For example, tissue ablation may be used to treat cardiac arrhythmias byat least partially destroying (e.g., at least partially or completelyablating, interrupting, inhibiting, terminating conduction of, otherwiseaffecting, etc.) aberrant pathways that would otherwise conduct abnormalelectrical signals to the heart muscle. Several ablation techniques havebeen developed, including cryoablation, microwave ablation, radiofrequency (RF) ablation, and high frequency ultrasound ablation. Forcardiac applications, such techniques are typically performed by aclinician who introduces a catheter having an ablative tip to theendocardium via the venous vasculature, positions the ablative tipadjacent to what the clinician believes to be an appropriate region ofthe endocardium based on tactile feedback, mapping electrocardiogram(ECG) signals, anatomy, and/or fluoroscopic imaging, actuates flow of anirrigant to cool the surface of the selected region, and then actuatesthe ablative tip for a period of time and at a power believed sufficientto destroy tissue in the selected region.

Successful electrophysiology procedures require precise knowledge aboutthe anatomic substrate. Additionally, ablation procedures may beevaluated within a short period of time after their completion. Cardiacablation catheters typically carry only regular mapping electrodes.Cardiac ablation catheters may incorporate high-resolution mappingelectrodes. Such high-resolution mapping electrodes provide moreaccurate and more detailed information about the anatomic substrate andabout the outcome of ablation procedures

SUMMARY

According to some embodiments, a device for high-resolution mapping andablating targeted tissue of subject comprises an elongate body (e.g., acatheter, another medical instrument, etc.) having a proximal end and adistal end, a first high-resolution electrode portion positioned on theelongate body, at least a second electrode portion positioned adjacentthe first electrode portion, the first and second electrode portionsbeing configured to contact tissue of a subject and deliverradiofrequency energy sufficient to at least partially ablate thetissue, and at least one electrically insulating gap positioned betweenthe first electrode portion and the second electrode portion, the atleast one electrically insulating gap comprising a gap width separatingthe first and second electrode portions, wherein the first electrodeportion is configured to electrically couple to the second electrodeportion using a filtering element, wherein the filtering element isconfigured to present a low impedance at a frequency used for deliveringablative energy via the first and second electrode portions, wherein thedevice is configured to be positioned within targeted tissue of thesubject to obtain high-resolution mapping data related to said tissuewhen ablative energy is not delivered to the first and second electrodeportions, wherein, based in part of the obtained mapping data, thedevice is configured to ablate one or more regions of the subject'stargeted tissue once ablative energy is delivered to the first and saidelectrode portions, and wherein the device is used as a roving device inconjunction with a separate mapping device or system to provide mappingdata in tissue regions not adequately covered by said separate mappingsystem, wherein the separate mapping device or system comprises aplurality of mapping electrodes.

According to some embodiments, the device additionally includes at leastone separator positioned within the at least one electrically insulatinggap, wherein the elongate body comprises at least one irrigationpassage, said at least one irrigation passage extending to the firstelectrode portion, wherein electrically separating the first and secondelectrode portions facilitates high-resolution mapping along a targetedanatomical area, wherein the filtering element comprises a capacitor,wherein the device comprises the filtering element, the filteringelement, wherein the filtering element is included on or within theelongate body, wherein the mapping electrodes of the separate mappingdevice or system are unipolar or bipolar electrodes, and wherein theseparate mapping device or system comprises a plurality of mappingelectrodes.

According to some embodiments, electrically separating the first andsecond electrode portions facilitates high-resolution mapping along atargeted anatomical area, and the separate mapping device or systemcomprises a plurality of mapping electrodes (e.g., a multi-electrodemapping system).

According to some embodiments, the device is used as a roving device inconjunction with a separate mapping device or system to provide mappingdata in tissue regions not adequately covered by said separate mappingsystem. In some embodiments, the separate mapping device or systemcomprises a plurality of mapping electrodes (e.g., unipolar or bipolarelectrodes). In some embodiments, the device comprises the filteringelement. In one embodiment, the filtering element is separate from thedevice. In some embodiments, the filtering element is included on orwithin the elongate body. In some embodiments, the filtering element isincluded on or within a proximal handle secured to the elongate body. Inseveral arrangements, the filtering element is included on or within agenerator configured to supply power to the first high-resolutionelectrode portion and the at least a second electrode portion.

According to some embodiments, the device additionally comprises a meansfor facilitating high-resolution mapping. In some embodiments,electrically separating the first and second electrode portionsfacilitates high-resolution mapping along a targeted anatomical area.

According to some embodiments, the device further includes at least oneseparator positioned within the at least one electrically insulatinggap. In one embodiment, the at least one separator contacts a proximalend of the first electrode portion and the distal end of the secondelectrode portion. In some embodiments, the filtering element comprisesa capacitor. In some embodiments, the capacitor comprises a capacitanceof 50 to 300 nF (e.g., approximately 100 nF, 50-75, 75-100, 100-150,150-200, 200-250, 250-300 nF, ranges between the foregoing, etc.). Inone embodiment, the capacitor comprises a capacitance of 100 nF. In somearrangements, a series impedance of lower than about 3 ohms (S2) isintroduced across the first and second electrodes in the operating RFfrequency range. In some embodiments, the operating RF frequency rangeis 300 kHz to 10 MHz. In some embodiments, the filtering elementcomprises a LC circuit.

According to some embodiments, the device additionally includes at leastone conductor configured to electrically couple an energy deliverymodule to at least one of the first and second electrode portions. Inone embodiment, the at least one conductor is electrically coupled to anenergy delivery module.

According to some embodiments, a frequency of energy provided to thefirst and second electrode portions is in the radiofrequency range. Insome embodiments, a series impedance introduced across the first andsecond electrode portions is lower than: (i) an impedance of a conductorthat electrically couples the electrodes to an energy delivery module,and (ii) an impedance of a tissue being treated. In some embodiments,the gap width is approximately 0.2 to 1.0 mm (e.g., 0.2-0.3, 0.3-0.4,0.4-0.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9, 0.9-1 mm, lengths betweenthe foregoing ranges, etc.). In one embodiment, the gap width is 0.5 mm.In some embodiments, the gap width is approximately 0.2 to 1.0 mm (e.g.,0.2-0.3, 0.3-0.4, 0.4-0.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9, 0.9-1.0mm, widths between the foregoing, etc.).

According to some embodiments, the elongate body comprises at least oneirrigation passage, the at least one irrigation passage extending to thefirst electrode portion. In some embodiments, the first electrodecomprises at least one outlet port in fluid communication with the atleast one irrigation passage. In one embodiment, the mapping electrodesof the separate mapping device or system are unipolar or bipolarelectrodes.

According to some embodiments, the device is configured to determinewhether tissue has been properly ablated. In some embodiments, adetermination of whether tissue has been properly ablated is determinedby comparing the amplitude of an electrogram obtained using the firstand second electrode portions to a baseline electrogram amplitude.

According to some embodiments, a method of mapping targeted anatomicaltissue of a subject and delivering energy to at least an area of saidanatomical tissue comprises positioning a high-resolution tip orhigh-resolution section electrode located on a catheter, thehigh-resolution tip or high-resolution section electrode comprising afirst electrode portion and a second electrode portion, wherein anelectrically insulating gap is positioned between the first electrodeportion and the second electrode portion, the electrically insulatinggap comprising a gap width separating the first and second electrodeportions, wherein a filtering element electrically couples the firstelectrode to the second electrode portion, and wherein electricallyseparating the first and second electrode portions facilitateshigh-resolution mapping along a targeted anatomical area.

According to some embodiments, the catheter comprises the filteringelement. In some embodiments, the filtering element is separate from thecatheter. In some embodiments, the method further includes receivinghigh-resolution mapping data from the first and second electrodeportions, the high-resolution mapping data relating to tissue of asubject adjacent the first and second electrode portions. In someembodiments, the high-resolution-tip or high-resolution-sectionelectrode is positioned in regions of a subject's tissue not mapped by aseparate mapping device or system. In some embodiments, thehigh-resolution-tip or high-resolution-section electrode is positionedwithout the use or assistance of a separate mapping device or system.

According to some embodiments, the first and second electrode portionsare configured to contact tissue of a subject and selectively deliverenergy sufficient to at least partially ablate tissue. In someembodiments, selectively delivering energy sufficient to at leastpartially ablate tissue is based, at least in part, of thehigh-resolution mapping of the targeted anatomical area obtained by thehigh-resolution tip or high-resolution section electrode located on thecatheter. In one embodiment, receiving high-resolution mapping dataoccurs prior to, during or after energizing a high-resolution tipelectrode positioned on a catheter.

According to some embodiments, the method additionally includescomprising determining whether tissue being mapped has been properlyablated. In some embodiments, determining whether tissue has beenproperly ablated comprises comparing the amplitude of an electrogramobtained using the first and second electrode portions to a baselineelectrogram amplitude.

According to some embodiments, a method of mapping tissue of a subjectcomprises receiving high-resolution mapping data using ahigh-resolution-tip or high-resolution-section electrode, saidhigh-resolution-tip or high-resolution-section electrode comprisingfirst and second electrode portions, wherein the high-resolution-tip orhigh-resolution-section electrode comprises a first electrode portionand a second electrode portion separated by an electrically insulatinggap, wherein a filtering element electrically couples the firstelectrode portion to the second electrode portion in the operating RFrange, and wherein electrically insulating the first and secondelectrode portions facilitates high-resolution mapping along a targetedanatomical area.

According to some embodiments, the filtering element is positionedadjacent the high-resolution-tip or the high-resolution-sectionelectrode. In some embodiments, the filtering element is separate oraway from the high-resolution-tip or the high-resolution-sectionelectrode. In some embodiments, the method further comprises energizingthe high-resolution-tip or high-resolution-section electrode toselectively deliver energy sufficient to at least partially ablate thetissue of the subject.

According to some embodiments, the high-resolution mapping data relatesto tissue of a subject adjacent the first and second electrode portions.In some embodiments, receiving high-resolution mapping data occurs priorto, during or after energizing a high-resolution tip or ahigh-resolution section electrode positioned on a catheter. In oneembodiment, the mapping data is provided to an electrophysiologyrecorder.

According to some embodiments, a frequency of energy provided to thefirst and second electrodes is in the radiofrequency range. In someembodiments, the filtering element comprises a capacitor. In someembodiments, the capacitor comprises a capacitance of 50 to 300 nF(e.g., approximately 100 nF, 50-75, 75-100, 100-150, 150-200, 200-250,250-300 nF, etc.). In one embodiment, the capacitor comprises acapacitance of 100 nF. In some arrangements, a series impedance of lowerthan about 3 ohms (S2) is introduced across the first and secondelectrodes in the operating RF frequency range. In some embodiments, theoperating RF frequency range is 300 kHz to 10 MHz. In some embodiments,the filtering element comprises a LC circuit.

According to some embodiments, a device on which the high-resolution-tipor high-resolution-section electrode is positioned is used as a rovingdevice in conjunction with a separate mapping device or system toprovide mapping data in tissue regions not adequately covered by saidseparate mapping device or system. In some embodiments, the separatemapping device or system comprises a plurality of mapping electrodes. Insome embodiments, the mapping electrodes of the separate mapping deviceor system are unipolar or bipolar electrodes.

According to some embodiments, a device on which the high-resolution-tipor high-resolution-section electrode is positioned is configured todetermine whether tissue has been properly ablated. In some embodiments,a determination of whether tissue has been properly ablated isdetermined by comparing the amplitude of an electrogram obtained usingthe first and second electrode portions to a baseline electrogramamplitude.

According to some embodiments, a system for obtaining mapping data for atargeted anatomical tissue of a subject comprises a data acquisitiondevice configured to receive mapping data from a first device, the firstdevice comprising at least one high-resolution electrode configured tomap tissue along the targeted anatomical tissue, wherein the dataacquisition device is further configured to receive mapping data from asecond device, the second device comprising a plurality of mappingelectrodes, and a processor configured to generate a three-dimensionalmap using the mapping data received by the data acquisition device fromthe first and second devices.

According to some embodiments, the first device comprises a catheter. Inone embodiment, the catheter comprises a high-resolution-tip electrode.In some embodiments, the second device comprises at least one expandablemember, wherein at least some of the plurality of mapping electrodes arepositioned along the at least one expandable member. In someembodiments, the mapping data received from the second device compriseunipolar signals. In some embodiments, the mapping data received fromthe second device comprise bipolar signals.

According to some embodiments, the processor is configured to align orsynchronize data obtained from the first and second devices. In someembodiments, the processor is configured to couple to an output devicefor displaying the three-dimensional map. In one embodiment, the systemcomprises the output device (e.g., monitor).

According to some embodiments, the system further comprises the firstdevice and/or the second devices. In some embodiments, the dataacquisition device and the processor are combined in a single assembly.In other arrangements, the data acquisition device and the processor areseparate.

According to some embodiments, a system for obtaining mapping data for atargeted anatomical tissue of a subject comprises a catheter includingat least one high-resolution electrode configured to map tissue alongthe targeted anatomical tissue, and a data acquisition device configuredto receive mapping data from the catheter, wherein the data acquisitiondevice is configured to couple to a separate mapping device, the dataacquisition device being configured to receive mapping data from theseparate mapping device, wherein the separate mapping device comprises aplurality of mapping electrodes. The system additionally includes aprocessor configured to generate a three-dimensional map from themapping data received from the catheter and the separate mapping deviceby the data acquisition device.

According to some embodiments, the catheter comprises ahigh-resolution-tip electrode. In some embodiments, the separate mappingsystem comprises at least one expandable member, wherein at least someof the plurality of mapping electrodes are positioned along the at leastone expandable member. In some embodiments, the mapping data receivedfrom the separate mapping device comprise unipolar signals. In someembodiments, the mapping data received from the separate mapping devicecomprise bipolar signals. In some embodiments, the processor isconfigured to align or synchronize mapping data obtained from thecatheter and the separate mapping device. In some embodiments, theprocessor is configured to couple to an output device for displaying thethree-dimensional map. In one embodiment, the system comprises theoutput device (e.g., one or more monitors). In some embodiments, theprocessor is integrated within the data acquisition device. In otherembodiments, the processor is separate from the data acquisition device.

According to some embodiments, a system for obtaining mapping data for atargeted anatomical tissue of a subject comprises a data acquisitiondevice configured to receive mapping data from a mapping catheter, and aprocessor configured to receive mapping data from the data acquisitiondevice and from a separate mapping system, wherein the separate mappingsystem is configured to operatively couple to the processor, theseparate mapping system comprising a plurality of mapping electrodes,and wherein the processor is configured to generate a three-dimensionalmap from such mapping data.

According to some embodiments, the system if configured to operativelycouple to an output device for displaying said three-dimensional map. Insome embodiments, the system further includes the output device (e.g.,one or more monitors or other displays). In some embodiments, the atleast one electrode of the catheter comprises a high-resolution-tipelectrode. In some embodiments, the at least one electrode of thecatheter comprises a bipolar electrode.

According to some embodiments, the separate mapping device comprises atleast one expandable member (e.g., strut, wire, cage, etc.), the atleast one expandable member comprising at least one of the plurality ofmapping electrodes. In some embodiments, the separate mapping devicecomprises an expandable basket or other expandable structure. In someembodiments, at least one of the mapping electrodes of the separatemapping device comprises a bipolar electrode. In some embodiments, atleast one of the mapping electrodes of the separate mapping devicecomprises a unipolar electrode. In some embodiments, the separatemapping device is configured to work with at least one referenceelectrode in order to generate the mapping data for the separate mappingdevice. In one embodiment, the at least one reference electrode islocated external to the subject. In some embodiments, the at least onereference electrode is located internal to the subject. In someembodiments, the at least one reference electrode is located within alumen of a subject. In some embodiments, the lumen of the subjectcomprises a superior vena cava of the subject.

According to some embodiments, the processor is configured to align orsynchronize data obtained from the catheter and from the separatedevice. In some embodiments, the system further comprises a user inputdevice (e.g., touchscreen, other keyboard or keypad, a computer, etc.)that allows a user to input information or data. In some embodiments,the processor is configured to operatively couple to a user inputdevice, the user input device allowing a user to input information ordata. In one embodiment, the user input device is incorporated into theoutput device. In some embodiments, the user input device is separatefrom the output device.

According to some embodiments, the at least one high-resolutionelectrode comprises a first high-resolution electrode portion. In someembodiments, the processor is integrated within the data acquisitiondevice. In some embodiments, the processor is separate from the dataacquisition device.

According to some embodiments, the system further includes the catheter.In some embodiments, the catheter comprises at least one high-resolutionelectrode configured to map tissue along the targeted anatomical tissue.In some embodiments, the separate mapping system comprises a separatedata acquisition device, the separate data acquisition device beingconfigured to receive data from the plurality of mapping electrodes ofsaid separate mapping system. In one embodiment, the separate dataacquisition system is configured to operatively couple to the processor.

According to some embodiments, a method of enhancing a map of a targetedanatomical region includes receiving mapping data from a first mappingdevice or system, the first mapping device or system comprising aplurality of mapping electrodes, receiving high-resolution mapping datafrom a second mapping system, the second mapping system being configuredto be moved to locations between the plurality of mapping electrodes ofthe first mapping system to obtain said high-resolution mapping data,wherein the second mapping device or system comprises a roving systemthat can be selectively positioned along a targeted anatomical region ofa subject, processing the mapping data obtained by the first and secondmapping devices or systems using a processor, wherein the second mappingdevice or system is configured to supplement and refine a map of thetargeted anatomical region, and creating an enhanced three-dimensionalmap using the processor with the data obtained by the first and secondmapping devices or systems.

According to some embodiments, the method further comprises displayingthe three-dimensional map (e.g., on a monitor or other display). In someembodiments, the method further comprises aligning or synchronizing thedata obtained from the plurality of mapping electrodes of the firstmapping device or system and from the high-resolution roving device orsystem. In some embodiments, the high-resolution mapping data isobtained using a high-resolution electrode of the second mapping deviceor system. In some embodiments, the data from the plurality of mappingelectrodes comprise unipolar signals. In some embodiments, the data fromthe plurality of mapping electrodes comprise bipolar signals.

According to some embodiments, the first mapping device or systemcomprises at least one expandable member, wherein at least some of themapping electrodes are located on the at least one expandable member. Insome embodiments, the targeted anatomical region is located along ornear the heart of a subject. In some embodiments, the targetedanatomical region comprises cardiac tissue. In some embodiments, thethree-dimensional map comprising at least one of an activation map, apropagation velocity map, a voltage map and a rotor map.

According to some embodiments, a method of creating an enhanced map of atargeted anatomical region includes collecting a first mapping data setfrom a plurality of mapping electrodes, collecting a second mapping dataset from a high-resolution roving electrode being configured to be movedto locations between the plurality of mapping electrodes, aligning orsynchronizing the first and second mapping data sets, and generating anenhanced three-dimensional map using the aligned or synchronized firstand second mapping data sets.

According to some embodiments, the method further includes displayingthe enhanced three-dimensional map. In one embodiment, data related tothe enhanced three-dimensional map are provided to an output device(e.g., monitor or other display) for displaying the three-dimensionalmap. In some embodiments, the data from the plurality of mappingelectrodes comprise unipolar signals. In some embodiments, the data fromthe plurality of mapping electrodes of the first mapping system comprisebipolar signals.

According to some embodiments, the plurality of mapping electrodes arepart of a multi-electrode mapping device or system, the multi-electrodedevice or system comprising at least one expandable member, wherein atleast some of the mapping electrodes are located on the at least oneexpandable member. In some embodiments, the roving system comprises acatheter, the catheter comprising at least one mapping electrode. In oneembodiment, the targeted anatomical region is located along or near theheart of a subject. In some embodiments, the targeted anatomical regioncomprises cardiac tissue. In some embodiments, the three-dimensional mapcomprising at least one of an activation map, a propagation velocitymap, a voltage map and a rotor map. In some embodiments.

According to some embodiments, a kit for obtaining mapping data oftissue comprises a device for high-resolution mapping in accordance withany one of the device configurations disclosed herein, and a separatemapping device or system, wherein the separate mapping device or systemcomprises a plurality of mapping electrodes configured to map tissue ofa subject, and wherein the device for high-resolution mapping providesmapping data in tissue regions not adequately covered by the separatemapping device or system.

According to some embodiments, a kit for obtaining mapping data oftissue comprises a device for high-resolution mapping, the deviceincluding an elongate body comprising a proximal end and a distal end, afirst high-resolution electrode portion positioned on the elongate body,at least a second electrode portion positioned adjacent the firstelectrode portion, the first and second electrode portions beingconfigured to contact tissue of a subject, and at least one electricallyinsulating gap positioned between the first electrode portion and thesecond electrode portion, the at least one electrically insulating gapcomprising a gap width separating the first and second electrodeportions, wherein the first electrode portion is configured toelectrically couple to the second electrode portion using a filteringelement, wherein the filtering element is configured to present a lowimpedance at a frequency used for delivering ablative energy via thefirst and second electrode portions, wherein the device is configured tobe positioned within targeted tissue of the subject to obtainhigh-resolution mapping data related to said tissue when ablative energyis not delivered to the first and second electrode portions. The kitfurther comprising a separate mapping device or system, wherein theseparate mapping device or system comprises a plurality of mappingelectrodes configured to map tissue of a subject, and wherein the devicefor high-resolution mapping provides mapping data in tissue regions notadequately covered by the separate mapping device or system.

According to some embodiments, the kit further includes a dataacquisition device configured to receive mapping data from the device,wherein the data acquisition device is further configured to receivemapping data from the separate mapping device or system. In someembodiments, the kit additionally comprises a processor configured togenerate a three-dimensional map using the mapping data received by thedata acquisition device from the device and from the separate mappingdevice or system. In some embodiments, the separate mapping device orsystem comprises at least one expandable member, wherein at least someof the plurality of mapping electrodes are positioned along the at leastone expandable member.

According to some embodiments, the mapping data received from theseparate mapping device or system comprise unipolar signals. In someembodiments, the mapping data received from the separate mapping deviceor system comprise bipolar signals. In some embodiments, the processoris configured to align or synchronize data obtained from the device andthe separate mapping device or system. In some embodiments, theprocessor is configured to couple to an output device for displaying thethree-dimensional map.

According to some embodiments, a processor for receiving and processingdata received from separate mapping devices or systems comprises a firstport configured to operatively connect to a first device forhigh-resolution mapping, the device comprising a catheter and anelectrode assembly for receiving high-resolution mapping data, and asecond port configured to operatively connect to a second mapping deviceor system, the second mapping device or system comprising a plurality ofelectrodes that are configured to contact various portions along atargeted region of tissue being mapped, wherein the processor isconfigured to combine mapping data obtained from the first device andfrom the second mapping device or system, and wherein the processor isconfigured to align the mapping data received from the first device andthe second mapping device or system to enable for the generation of amore complete three-dimensional map of tissue being mapped. In someembodiments, the processor is configured to be operatively coupled to anoutput device (e.g., at least one monitor or other display) fordisplaying the three-dimensional map created from data of both the firstdevice and the second device or system.

According to some embodiments, a generator for selectively deliveringenergy to an ablation device comprises a processor according to any oneof the embodiments disclosed herein, and an energy delivery moduleconfigured to generate ablative energy for delivery to an ablationdevice, wherein ablative energy generated by the energy delivery moduleis delivered to and through the first device to the electrode assemblyof the first device. In some embodiments, the energy delivery module isconfigured to generated radiofrequency (RF) energy. In some embodiments,the processor and the energy delivery module are located within a singlehousing or enclosure. In some embodiments, the processor and the energydelivery module are located within separate housings or enclosures

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentapplication are described with reference to drawings of certainembodiments, which are intended to illustrate, but not to limit, theconcepts disclosed herein. The attached drawings are provided for thepurpose of illustrating concepts of at least some of the embodimentsdisclosed herein and may not be to scale:

FIG. 1 schematically illustrates one embodiment of an energy deliverysystem configured to selectively ablate or otherwise heat targetedtissue of a subject;

FIG. 2 illustrates a side view of a system's catheter comprises ahigh-resolution-tip design according to one embodiment;

FIG. 3 illustrates a side view of a system's catheter comprises ahigh-resolution-tip design according to another embodiment;

FIG. 4 illustrates a side view of a system's catheter comprises ahigh-resolution-tip design according to yet another embodiment;

FIG. 5 illustrates an embodiment of a system's catheter comprising twohigh-resolution-section electrodes each consisting of separate sectionscircumferentially distributed on the catheter shaft;

FIG. 6 schematically illustrates one embodiment of a high-pass filteringelement consisting of a coupling capacitor. The filtering element can beincorporated into a system's catheter that comprises ahigh-resolution-tip design;

FIG. 7 schematically illustrates one embodiment of four high-passfiltering elements comprising coupling capacitors. The filteringelements can operatively couple, in the operating RF frequency range,the separate electrode sections of a system's catheter electrodes, e.g.,those illustrated in FIG. 5;

FIG. 8 illustrates embodiments of EKGs obtained from ahigh-resolution-tip electrode systems disclosed herein configured todetect whether an ablation procedure has been adequately performed;

FIG. 9 illustrates one embodiment of a commercially-available mappingsystem comprising a plurality of mapping electrodes;

FIG. 10 illustrates one embodiment of intermediate locations that can bemapped by an embodiment of a high-resolution-tip system disclosed hereinto obtain a more accurate and comprehensive map of treated tissue;

FIG. 11 illustrates a schematic of a mapping system configured to obtaintissue mapping data using at least two different devices according toone embodiment;

FIG. 12 schematically illustrates one embodiment of an enhanced mappingsystem that includes a mapping system having a plurality of mappingelectrodes and a roving system;

FIG. 13 illustrates one embodiment of an algorithm used by an enhancedmapping system to create an enhanced 3D map of a targeted anatomicalregion being mapped;

FIG. 14 illustrates electrocardiograms received from two differentmapping devices of a system, according to one embodiment;

FIG. 15A illustrates one embodiment of a 3D tissue map obtained usingonly a multi-electrode mapping system;

FIG. 15B illustrates the 3D tissue map of FIG. 15A that has beenenhanced by high-resolution data obtained using a second mapping device,according to one embodiment;

FIG. 16 schematically illustrates an alternate embodiment of a filteringelement comprising a circuit configured to be used with any of thedevices and systems disclosed herein to facilitate high resolutionmapping; and

FIG. 17 illustrates one embodiment of a chart depicting impedancemagnitude at different frequencies for the filtering element of FIG. 16.

DETAILED DESCRIPTION

According to some embodiments, successful electrophysiology proceduresrequire precise knowledge about the anatomic substrate being targeted.Additionally, it may be desirable to evaluate the outcome of an ablationprocedure within a short period of time after the execution of theprocedure (e.g., to confirm that the desired clinical outcome wasachieved). Typically, ablation catheters include only regular mappingelectrodes (e.g., ECG electrodes). However, in some embodiments, it maybe desirable for such catheters to incorporate high-resolution mappingcapabilities. In some arrangements, high-resolution mapping electrodescan provide more accurate and more detailed information about theanatomic substrate and about the outcome of ablation procedures. Forexample, such high-resolution mapping electrodes can allow theelectrophysiology (EP) practitioner to evaluate the morphology ofelectrograms, their amplitude and width and/or to determine changes inpacing thresholds. According to some arrangements, morphology, amplitudeand/or pacing threshold are accepted as reliable EP markers that provideuseful information about the outcome of ablation

Several embodiments disclosed herein are particularly advantageousbecause they include one, several or all of the following benefits oradvantages: reducing proximal edge heating, reducing the likelihood ofchar formation, providing for feedback that may be used to adjustablation procedures in real time, providing noninvasive temperaturemeasurements, providing for the creation of a more complete andcomprehensive map (e.g., three-dimensional map) of tissue beingevaluated, providing for more targeted ablation of tissue to treat acondition (e.g., atrial fibrillation, other cardiac arrhythmias, etc.)based on the more complete map of tissue, providing for integration(e.g., seamless or near seamless integration) with a separate mappingsystem, providing safer and more reliable ablation procedures and/or thelike.

According to some embodiments, various implementations of electrodes(e.g., radiofrequency or RF electrodes) that can be used forhigh-resolution mapping are disclosed herein. For example, as discussedin greater detail herein, an ablation or other energy delivery systemcan comprise a high-resolution-tip design, wherein the energy deliverymember (e.g., radiofrequency electrode) comprises two or more separateelectrodes or electrode portions. As also discussed herein, in someembodiments, such separate electrodes or electrode portions can beadvantageously electrically coupled to each other (e.g., to collectivelycreate the desired heating or ablation of targeted tissue).

FIG. 1 schematically illustrates one embodiment of an energy deliverysystem 10 that is configured to selectively ablate, stimulate, modulateand/or otherwise heat or treat targeted tissue (e.g., cardiac tissue,pulmonary vein, other vessels or organs, etc.). Although certainembodiments disclosed herein are described with reference to ablationsystems and methods, any of the systems and methods can be used tostimulate, modulate, heat and/or otherwise affect tissue, with orwithout partial or complete ablation, as desired or required. As shown,the system 10 can include a medical instrument 20 (e.g., catheter)comprising one or more energy delivery members 30 (e.g., radiofrequencyelectrodes) along a distal end of the medical instrument 20. The medicalinstrument can be sized, shaped and/or otherwise configured to be passedintraluminally (e.g., intravascularly) through a subject being treated.In various embodiments, the medical instrument 20 comprises a catheter,a shaft, a wire, and/or other elongate instrument. In other embodiments,the medical instrument is not positioned intravascularly but ispositioned extravascularly via laparoscopic or open surgical procedures.In various embodiments, the medical instrument 20 comprises a catheter,a shaft, a wire, and/or other elongate instrument. In some embodiments,one or more temperature sensing devices or systems 60 (e.g.,thermocouples, thermistors, etc.) may be included at the distal end ofthe medical instrument 20, or along its elongate shaft or in its handle.The term “distal end” does not necessarily mean the distal terminus ordistal end. Distal end could mean the distal terminus or a locationspaced from the distal terminus but generally at a distal end portion ofthe medical instrument 20.

In some embodiments, the medical instrument 20 is operatively coupled toone or more devices or components. For example, as depicted in FIG. 1,the medical instrument 20 can be coupled to a delivery module 40 (suchas an energy delivery module). According to some arrangements, theenergy delivery module 40 includes an energy generation device 42 thatis configured to selectively energize and/or otherwise activate theenergy delivery member(s) 30 (for example, radiofrequency electrodes)located along the medical instrument 20. In some embodiments, forinstance, the energy generation device 42 comprises a radiofrequencygenerator, an ultrasound energy source, a microwave energy source, alaser/light source, another type of energy source or generator, and thelike, and combinations thereof. In other embodiments, energy generationdevice 42 is substituted with or use in addition to a source of fluid,such a cryogenic fluid or other fluid that modulates temperature.Likewise, the delivery module (e.g., delivery module 40), as usedherein, can also be a cryogenic device or other device that isconfigured for thermal modulation.

With continued reference to the schematic of FIG. 1, the energy deliverymodule 40 can include one or more input/output devices or components 44,such as, for example, a touchscreen device, a screen or other display, acontroller (e.g., button, knob, switch, dial, etc.), keypad, mouse,joystick, trackpad, or other input device and/or the like. Such devicescan permit a physician or other user to enter information into and/orreceive information from the system 10. In some embodiments, the outputdevice 44 can include a touchscreen or other display that providestissue temperature information, contact information, other measurementinformation and/or other data or indicators that can be useful forregulating a particular treatment procedure.

According to some embodiments, the energy delivery module 40 includes aprocessor 46 (e.g., a processing or control unit) that is configured toregulate one or more aspects of the treatment system 10. The module 40can also comprise a memory unit or other storage device 48 (e.g.,computer readable medium) that can be used to store operationalparameters and/or other data related to the operation of the system 10.In some embodiments, the processor 46 is configured to automaticallyregulate the delivery of energy from the energy generation device 42 tothe energy delivery member 30 of the medical instrument 20 based on oneor more operational schemes. For example, energy provided to the energydelivery member 30 (and thus, the amount of heat transferred to or fromthe targeted tissue) can be regulated based on, among other things, thedetected temperature of the tissue being treated.

According to some embodiments, the energy delivery system 10 can includeone or more temperature detection devices, such as, for example,reference temperature devices (e.g., thermocouples, thermistors, etc.)and/or the like. For example, in some embodiments, the device furthercomprises a one or more temperature sensors or othertemperature-measuring devices to help determine a peak (e.g., high orpeak, low or trough, etc.) temperature of tissue being treated. In someembodiments, the temperature sensors (e.g., thermocouples) located at,along and/or near the ablation member (e.g., RF electrode) can help withthe determination of whether contact is being made between the ablationmember and targeted tissue (and/or to what degree such contact is beingmade). In some embodiments, such peak temperature is determined withoutthe use of radiometry.

With reference to FIG. 1, the energy delivery system 10 comprises (or isin configured to be placed in fluid communication with) an irrigationfluid system 70. In some embodiments, as schematically illustrated inFIG. 1, such a fluid system 70 is at least partially separate from theenergy delivery module 40 and/or other components of the system 10.However, in other embodiments, the irrigation fluid system 70 isincorporated, at least partially, into the energy delivery module 40.The irrigation fluid system 70 can include one or more pumps or otherfluid transfer devices that are configured to selectively move fluidthrough one or more lumens or other passages of the catheter 20. Suchfluid can be used to selectively cool (e.g., transfer heat away from)the energy delivery member 30 during use.

FIG. 2 illustrates one embodiment of a distal end of a medicalinstrument (e.g., catheter) 20. As shown, the catheter 20 can include ahigh-resolution tip design, such that there are two adjacent electrodesor two adjacent electrode portions 30A, 30B separated by a gap G.According to some embodiments, as depicted in the configuration of FIG.2, the relative length of the different electrodes or electrode portions30A, 30B can vary. For example, the length of the proximal electrode 30Bcan be between 1 to 20 times (e.g., 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8,8-9, 9-10, 10-11, 11-12, 12-13, 13-14, 14-15, 15-16, 16-17, 17-18,18-19, 19-20, values between the foregoing ranges, etc.) the length ofthe distal electrode 30A, as desired or required. In other embodiments,the length of the proximal electrode 30B can be greater than 20 times(e.g., 20-25, 25-30, more than 30 times, etc.) the length of the distalelectrode 30A. In yet other embodiments, the lengths of the distal andproximal electrodes 30A, 30B are about equal. In some embodiments, thedistal electrode 30A is longer than the proximal electrode 30B (e.g., by1 to 20 times, such as, for example, 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8,8-9, 9-10, 10-11, 11-12, 12-13, 13-14, 14-15, 15-16, 16-17, 17-18,18-19, 19-20, values between the foregoing ranges, etc.).

In some embodiments, the distal electrode or electrode portion 30A is0.5 mm long. In other embodiments, the distal electrode or electrodeportion 30A is between 0.1 mm and 1 mm long (e.g., 0.1-0.2, 0.2-0.3,0.3-0.4, 0.4-0.5, 0.5-0.6, 0.6-0.7, 0.-0.8, 0.8-0.9, 0.9-1 mm, valuesbetween the foregoing ranges, etc.). In other embodiments, the distalelectrode or electrode portion 30A is greater than 1 mm in length, asdesired or required. In some embodiments, the proximal electrode orelectrode portion 30B is 2 to 4 mm long (e.g., 2-2.5, 2.5-3, 3-3.5,3.5-4 mm, lengths between the foregoing, etc.). However, in otherembodiments, the proximal electrode portion 30B is greater than 4 mm(e.g., 4-5, 5-6, 6-7, 7-8, 8-9, 9-10 mm, greater than 10 mm, etc.) orsmaller than 1 mm (e.g., 0.1-0.5 0.5-1, 1-1.5, 1.5-2 mm, lengths betweenthe foregoing ranges, etc.), as desired or required. In embodimentswhere the high-resolution electrodes are located on catheter shafts, thelength of the electrodes can be 1 to 5 mm (e.g., 1-2, 2-3, 3-4, 4-5 mm,lengths between the foregoing, etc.). However, in other embodiments, theelectrodes can be longer than 5 mm (e.g., 5-6, 6-7, 7-8, 8-9, 9-10,10-15, 15-20 mm, lengths between the foregoing, lengths greater than 20mm, etc.), as desired or required.

As noted above, the use of a high-resolution tip design can permit auser to simultaneously ablate or otherwise thermally treat targetedtissue and map (e.g., using high-resolution mapping) in a singleconfiguration. Thus, such systems can advantageously permit precisehigh-resolution mapping (e.g., to confirm that a desired level oftreatment occurred) during a procedure. In some embodiments, thehigh-resolution tip design that includes two electrodes or electrodeportions 30A, 30B can be used to record a high-resolution bipolarelectrogram. For such purposes, the two electrodes or electrode portionscan be connected to the inputs of an EP recorder. In some embodiments, arelatively small separation distance (e.g., gap G) between theelectrodes or electrode portions 30A, 30B enables high-resolutionmapping.

In some embodiments, a medical instrument (e.g., a catheter) 20 caninclude three or more electrodes or electrode portions (e.g., separatedby gaps), as desired or required. Additional details regarding sucharrangements are provided below. According to some embodiments,regardless of how many electrodes or electrode portions are positionedalong a catheter tip, the electrodes or electrode portions 30A, 30B areradiofrequency electrodes and comprise one or more metals, such as, forexample, stainless steel, platinum, platinum-iridium, gold, gold-platedalloys and/or the like.

According to some embodiments, as illustrated in FIG. 2, the electrodesor electrode portions 30A, 30B are spaced apart from each other (e.g.,longitudinally or axially) using a gap (e.g., an electrically insulatinggap). In some embodiments, the length of the gap G (or the separationdistance between adjacent electrodes or electrode portions) is 0.5 mm.In other embodiments, the gap G or separation distance is greater orsmaller than 0.5 mm, such as, for example, 0.1-1 mm (e.g., 0.1-0.2,0.2-0.3, 0.3-0.4, 0.4-0.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9, 0.9-1.0mm, values between the foregoing ranges, less than 0.1 mm, greater than1 mm, etc.), as desired or required.

According to some embodiments, a separator 34 is positioned within thegap G, between the adjacent electrodes or electrode portions 30A, 30B,as depicted in FIG. 2. The separator can comprise one or moreelectrically insulating materials, such as, for example, Teflon,polyetheretherketone (PEEK), polyetherimide resins (e.g., ULTEMTM),ceramic materials, polyimide and the like.

As noted above with respect to the gap G separating the adjacentelectrodes or electrode portions, the insulating separator 34 can be 0.5mm long. In other embodiments, the length of the separator 34 can begreater or smaller than 0.5 mm (e.g., 0.1-0.2, 0.2-0.3, 0.3-0.4,0.4-0.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9, 0.9-1.0 mm, values betweenthe foregoing ranges, less than 0.1 mm, greater than 1 mm, etc.), asdesired or required.

According to some embodiments, as discussed in greater detail herein, toablate or otherwise heat or treat targeted tissue of a subjectsuccessfully with the high-resolution tip electrode design, such as theone depicted in FIG. 2, the two electrodes or electrode portions 30A,30B are electrically coupled to each other at the RF frequency. Thus,the two electrodes or electrode portions can advantageously function asa single longer electrode at the RF frequency.

FIGS. 3 and 4 illustrate different embodiments of catheter systems 100,200 that incorporate a high-resolution tip design. For example, in FIG.3, the electrode (e.g., radiofrequency electrode) along the distal endof the electrode comprises a first or distal electrode or electrodeportion 110 and a second or proximal electrode or electrode portion 114.As shown and discussed in greater detail herein with reference to otherconfigurations, the high-resolution tip design 100 includes a gap Gbetween the first and second electrodes or electrode portions 110, 114.In some configurations, the second or proximal electrode or electrodeportion 114 is generally longer than the first or distal electrode orelectrode portion 110. For instance, the length of the proximalelectrode 114 can be between 1 to 20 times (e.g., 1-2, 2-3, 3-4, 4-5,5-6, 6-7, 7-8, 8-9, 9-10, 10-11, 11-12, 12-13, 13-14, 14-15, 15-16,16-17, 17-18, 18-19, 19-20, values between the foregoing ranges, etc.)the length of the distal electrode 110, as desired or required. In otherembodiments, the length of the proximal electrode can be greater than 20times (e.g., 20-25, 25-30, more than 30 times, etc.) the length of thedistal electrode. In yet other embodiments, the lengths of the distaland proximal electrodes are about the same. However, in someembodiments, the distal electrode 110 is longer than the proximalelectrode 114 (e.g., by 1 to 20 times, such as, for example, 1-2, 2-3,3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10, 10-11, 11-12, 12-13, 13-14, 14-15,15-16, 16-17, 17-18, 18-19, 19-20, values between the foregoing ranges,etc.).

As shown in FIG. 3 and noted above, regardless of their exact design,relative length diameter, orientation and/or other characteristics, theelectrodes or electrode portions 110, 114 can be separated by a gap G.The gap G can comprise a relatively small electrically insulating gap orspace. In some embodiments, an electrically insulating separator 118 canbe snugly positioned between the first and second electrodes orelectrode portions 110, 114. In certain embodiments, the separator 118can have a length of about 0.5 mm. In other embodiments, however, thelength of the separator 118 can be greater or smaller than 0.5 mm (e.g.,0.1-0.2, 0.2-0.3, 0.3-0.4, 0.4-0.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9,0.9-1.0 mm, values between the foregoing ranges, less than 0.1 mm,greater than 1 mm, etc.), as desired or required. The separator caninclude one or more electrically insulating materials (e.g., materialsthat have an electrical conductivity less than about 1000 or less (e.g.,500-600, 600-700, 700-800, 800-900, 900-1000, 1000-1100, 1100-1200,1200-1300, 1300-1400, 1400-1500, values between the foregoing, less than500, greater than 1500, etc.) than the electrical conductivity of metalsor alloys). The separator can comprise one or more electricallyinsulating materials, such as, for example, Teflon, polyetheretherketone(PEEK), polyoxymethylene, acetal resins or polymers and the like.

As shown in FIG. 3, the separator 118 can be cylindrical in shape andcan have the identical or similar diameter and configuration as theadjacent electrodes or electrode portions 110, 114. Thus, in someembodiments, the outer surface formed by the electrodes or electrodeportions 110, 114 and the separator 118 can be generally uniform orsmooth. However, in other embodiments, the shape, size (e.g., diameter)and/or other characteristics of the separator 118 can be different thanone or more of the adjacent electrodes or electrode portions 110, 114,as desired or required for a particular application or use.

FIG. 4 illustrates an embodiment of a system 200 having three or moreelectrodes or electrode portions 210, 212, 214 separated bycorresponding gaps G1, G2. The use of such additional gaps, and thus,additional electrodes or electrode portions 210, 212, 214 that arephysically separated (e.g., by gaps) yet in close proximity to eachother, can provide additional benefits to the high-resolution mappingcapabilities of the system. For example, the use of two (or more) gapscan provide more accurate high-resolution mapping data related to thetissue being treated. Such multiple gaps can provide information aboutthe directionality of cardiac signal propagation. In addition,high-resolution mapping with high-resolution electrode portionsinvolving multiple gaps can provide a more extended view of lesionprogression during the ablation process and higher confidence thatviable tissue strands are not left behind within the targetedtherapeutic volume. In some embodiments, high-resolution electrodes withmultiple gaps can optimize the ratio of mapped tissue surface to ablatedtissue surface. Preferably, such ratio is in the range of 0.2 to 0.8(e.g., 0.2-0.3, 0.3-0.4, 0.4-.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, ratiosbetween the foregoing, etc.). Although FIG. 4 illustrates an embodimenthaving a total of three electrodes or electrode portions 210, 212, 214(and thus, two gaps G1, G2), a system can be designed or otherwisemodified to comprise additional electrodes or electrode portions, andthus, additional gaps. For example, in some embodiments, an ablation orother treatment system can include 4 or more (e.g., 5, 6, 7, 8, morethan 8, etc.) electrodes or electrode portions (and thus, 3 or moregaps, e.g., 3, 4, 5, 6, 7 gaps, more than 7 gaps, etc.), as desired orrequired. In such configurations, a gap (and/or an electrical separator)can be positioned between adjacent electrodes or electrode portions, inaccordance with the embodiments illustrated in FIGS. 2 to 4.

As depicted in FIGS. 3 and 4, an irrigation tube 120, 220 can be routedwithin an interior of the catheter (not shown for clarity). In someembodiments, the irrigation tube 120, 220 can extend from a proximalportion of the catheter (e.g., where it can be placed in fluidcommunication with a fluid pump) to the distal end of the system. Forexample, in some arrangements, as illustrated in the side views of FIGS.3 and 4, the irrigation tube 120, 220 extends and is in fluidcommunication with one or more fluid ports 211 that extend radiallyoutwardly through the distal electrode 110, 210. Thus, in someembodiments, the treatment system comprises an open irrigation design,wherein saline and/or other fluid is selectively delivered through thecatheter (e.g., within the fluid tube 120, 220) and radially outwardlythrough one or more outlet ports 111, 211 of an electrode 110, 210. Thedelivery of such saline or other fluid can help remove heat away fromthe electrodes and/or the tissue being treated. In some embodiments,such an open irrigation system can help prevent or reduce the likelihoodof overheating of targeted tissue, especially along the tissue that iscontacted by the electrodes. An open irrigation design is alsoincorporated in the system that is schematically illustrated in FIG. 2.For instance, as depicted in FIG. 2, the distal electrode or electrodeportion 34 can include a plurality of outlet ports 36 through whichsaline or other irrigation fluid can exit.

According to some embodiments, a catheter can include ahigh-resolution-tip electrode design that includes one or more gaps inthe circumferential direction (e.g., radially), either in addition to orin lieu of gaps in the longitudinal direction. One embodiment of asystem 300 comprising one or more electrodes 310A, 310B is illustratedin FIG. 5. As shown, in arrangements where two or more electrodes areincluded, the electrodes 310A, 310B can be longitudinally or axiallyoffset from each other. For example, in some embodiments, the electrodes310A, 310B are located along or near the distal end of a catheter. Insome embodiments, the electrodes 310A, 310B are located along anexterior portion of a catheter or other medical instrument. However, inother configurations, one or more of the electrodes can be positionedalong a different portion of the catheter or other medical instrument(e.g., along at least an interior portion of a catheter), as desired orrequired.

With continued reference to FIG. 5, each electrode 310A, 310B cancomprises two or more sections 320A, 322A and/or 320B, 320B. As shown,in some embodiments, the each section 320A, 322A and/or 320B, 320B canextend half-way around (e.g., 180 degrees) the diameter of the catheter.However, in other embodiments, the circumferential extent of eachsection can be less than 180 degrees. For example, each section canextend between 0 and 180 degrees (e.g., 15, 30, 45, 60, 75, 90, 105, 120degrees, degrees between the foregoing, etc.) around the circumferenceof the catheter along which it is mounted. Thus, in some embodiments, anelectrode can include 2, 3, 4, 5, 6 or more circumferential sections, asdesired or required.

Regardless of how the circumferential electrode sections are designedand oriented, electrically insulating gaps G can be provided betweenadjacent sections to facilitate the ability to use the electrode toconduct high-resolution mapping, in accordance with the variousembodiments disclosed herein. Further, as illustrated in the embodimentof FIG. 5, two or more (e.g., 3, 4, 5, more than 5, etc.) electrodes310A, 310B having two or more circumferential or radial sections can beincluded in a particular system 300, as desired or required.

In alternative embodiments, the various embodiments of a high-resolutiontip design disclosed herein, or variations thereof, can be used with anon-irrigated system or a closed-irrigation system (e.g., one in whichsaline and/or other fluid is circulated through or within one or moreelectrodes to selectively remove heat therefrom). Thus, in somearrangements, a catheter can include two or more irrigation tubes orconduits. For example, one tube or other conduit can be used to deliverfluid toward or near the electrodes, while a second tube or otherconduit can be used to return the fluid in the reverse direction throughthe catheter.

According to some embodiments, a high-resolution tip electrode isdesigned to balance the current load between the various electrodes orelectrode portions. For example, if a treatment system is not carefullyconfigured, the electrical load may be delivered predominantly to one ormore of the electrodes or electrode portions of the high-resolution tipsystem (e.g., the shorter or smaller distal electrode or electrodeportion). This can lead to undesirable uneven heating of the electrode,and thus, uneven heating (e.g., ablation) of the adjacent tissue of thesubject. Thus, in some embodiments, one or more load balancingconfigurations can be used to help ensure that the heating along thevarious electrodes or electrode portions of the system will be generallybalanced. As a result, the high-resolution tip design can advantageouslyfunction more like a longer, single electrode, as opposed to two or moreelectrodes that receive an unequal electrical load (and thus, deliver anunequal amount of heat or level of treatment to the subject's targetedtissue).

One embodiment of a configuration that can be used to balance theelectrical current load delivered to each of the electrodes or electrodeportions in a high-resolution tip design is schematically illustrated inFIG. 6. As shown, one of the electrodes (e.g., the distal electrode) 30Acan be electrically coupled to an energy delivery module 40 (e.g., a RFgenerator). As discussed herein, the module 40 can comprise one or morecomponents or features, such as, for example, an energy generationdevice that is configured to selectively energize and/or otherwiseactivate the energy members (e.g., RF electrodes), one or moreinput/output devices or components, a processor (e.g., a processing orcontrol unit) that is configured to regulate one or more aspects of thetreatment system, a memory and/or the like. Further, such a module canbe configured to be operated manually or automatically, as desired orrequired.

In the embodiment that is schematically depicted in FIG. 6, the distalelectrode 30A is energized using one or more conductors 82 (e.g., wires,cables, etc.). For example, in some arrangements, the exterior of theirrigation tube 38 comprises and/or is otherwise coated with one or moreelectrically conductive materials (e.g., copper, other metal, etc.).Thus, as shown in FIG. 6, the conductor 82 can be placed in contact withsuch a conductive surface or portion of the tube 38 to electricallycouple the electrode or electrode portion 30A to an energy deliverymodule. However, one or more other devices and/or methods of placing theelectrode or electrode portion 30A in electrical communication with anenergy delivery module can be used. For example, one or more wires,cables and/or other conductors can directly or indirectly couple to theelectrodes, without the use of the irrigation tube.

With continued reference to FIG. 6, the first or distal electrode orelectrode portion 30A can be electrically coupled to the second orproximal electrode or electrode portion 30B using one more band-passfiltering elements 84, such as a capacitor, a filter circuit (see, e.g.,FIG. 16), etc. For instance, in some embodiments, the band-passfiltering element 84 comprises a capacitor that electrically couples thetwo electrodes or electrode portions 30A, 30B when radiofrequencycurrent is applied to the system. In one embodiment, the capacitor 84comprises a 100 nF capacitor that introduces a series impedance lowerthan about 3Ω at 500 kHz, which, according to some arrangements, is atarget frequency for RF ablation. However, in other embodiments, thecapacitance of the capacitor(s) or other band-pass filtering elements 84that are incorporated into the system can be greater or less than 100nF, for example, 5 nF to 300 nF, according to the operating RFfrequency, as desired or required. In some embodiments, the capacitanceof the filtering element 84 is selected based on a target impedance at aparticular frequency or frequency range. For example, in someembodiments, the system can be operated at a frequency of 200 kHz to 10MHz (e.g., 200-300, 300-400, 400-500, 500-600, 600-700, 700-800,800-900, 900-1000 kHz, up to 10 MHz or higher frequencies between theforegoing ranges, etc.). Thus, the capacitor that couples adjacentelectrodes or electrode portions to each other can be selected based onthe target impedance for a particular frequency. For example, a 100 nFcapacitor provides about 3Ω of coupling impedance at an operatingablation frequency of 500 kHz.

In some embodiments, a series impedance of 3Ω across the electrodes orelectrode portions 30A, 30B is sufficiently low when compared to theimpedance of the conductor 82 (e.g., wire, cable, etc.), which can beabout 5-10Ω, and the impedance of tissue, which can be about 100Ω, suchthat the resulting tissue heating profile is not negatively impactedwhen the system is in use. Thus, in some embodiments, a filteringelement is selected so that the series impedance across the electrodesor electrode portions is lower than the impedance of the conductor thatsupplies RF energy to the electrodes. For example, in some embodiments,the insertion impedance of the filtering element is 50% of the conductor82 impedance, or lower, or 10% of the equivalent tissue impedance, orlower.

In some embodiments, a filtering element (e.g., capacitor a filtercircuit such as the one described herein with reference to FIG. 16,etc.) can be located at a variety of locations of the device oraccompanying system. For example, in some embodiments, the filteringelement is located on or within a catheter (e.g., near the distal end ofthe catheter, adjacent the electrode, etc.). In other embodiments,however, the filtering element is separate of the catheter. Forinstance, the filtering element can be positioned within or along ahandle to which the catheter is secured, within the generator or otherenergy delivery module, within a separate processor or other computingdevice or component and/or the like).

Similarly, with reference to the schematic of FIG. 7, a filteringelement 384 can be included in an electrode 310 comprisingcircumferentially-arranged portions 320, 322. In FIG. 7, the filteringelement 384 permits the entire electrode 310 to be energized within RFfrequency range (e.g., when the electrode is activated to ablate). Oneor more RF wires or other conductors 344 can be used to deliver power tothe electrode from a generator or source. In addition, separateconductors 340 can be used to electrically couple the electrode 310 formapping purposes.

In embodiments where the high-resolution-tip design (e.g., FIG. 4)comprises three or more electrodes or electrode portions, additionalfiltering elements (e.g., capacitors) can be used to electrically couplethe electrodes or electrode portions to each other. Such capacitors orother filtering elements can be selected to create a generally uniformheating profile along the entire length of the high-resolution tipelectrode. As noted in greater detail herein, for any of the embodimentsdisclosed herein or variations thereof, the filtering element caninclude something other than a capacitor. For example, in somearrangements, the filtering element comprises a LC circuit (e.g., aresonant circuit, a tank circuit, a tuned circuit, etc.). Suchembodiments can be configured to permit simultaneous application of RFenergy and measurement of EGM recordings.

As discussed above, the relatively small gap G between the adjacentelectrodes or electrode portions 30A, 30B can be used to facilitatehigh-resolution mapping of the targeted tissue. For example, withcontinued reference to the schematic of FIG. 6, the separate electrodesor electrode portions 30A, 30B can be used to generate an electrogramthat accurately reflects the localized electrical potential of thetissue being treated. Thus, a physician or other practitioner using thetreatment system can more accurately detect the impact of the energydelivery to the targeted tissue before, during and/or after a procedure.For example, the more accurate electrogram data that result from suchconfigurations can enable the physician to detect any gaps or portionsof the targeted anatomical region that was not properly ablated orotherwise treated. Specifically, the use of a high-resolution tip designcan enable a cardiac electrophysiologist to more accurately evaluate themorphology of resulting electrograms, their amplitude and width and/orto determine pacing thresholds. In some embodiments, morphology,amplitude and pacing threshold are accepted and reliable EP markers thatprovide useful information about the outcome of an ablation or otherheat treatment procedure.

According to some arrangements, the high-resolution-tip electrodeembodiments disclosed herein are configured to provide localizedhigh-resolution electrogram. For example, the electrogram that isobtained using a high-resolution-tip electrode, in accordance withembodiments disclosed herein, can provide electrogram data (e.g.,graphical output) 400 a, 400 b as illustrated in FIG. 8. As depicted inFIG. 8, the localized electrograms 400 a, 400 b generated using thehigh-resolution-tip electrode embodiments disclosed herein include anamplitude A1, A2.

With continued reference to FIG. 8, the amplitude of the electrograms400 a, 400 b obtained using high-resolution-tip electrode systems can beused to determine whether targeted tissue adjacent thehigh-resolution-tip electrode has been adequately ablated or otherwisetreated. For example, according to some embodiments, the amplitude A1 ofan electrogram 400 a in untreated tissue (e.g., tissue that has not beenablated or otherwise heated) is greater that the amplitude A2 of anelectrogram 400 b that has already been ablated or otherwise treated. Insome embodiments, therefore, the amplitude of the electrogram can bemeasured to determine whether tissue has been treated. For example, theelectrogram amplitude A1 of untreated tissue in a subject can berecorded and used as a baseline. Future electrogram amplitudemeasurements can be obtained and compared against such a baselineamplitude in an effort to determine whether tissue has been ablated orotherwise treated to an adequate or desired degree.

In some embodiments, a comparison is made between such a baselineamplitude (A1) relative to an electrogram amplitude (A2) at a tissuelocation being tested or evaluated. A ratio of A1 to A2 can be used toprovide a quantitative measure for assessing the likelihood thatablation has been completed. In some arrangements, if the ratio (i.e.,A1/A2) is above a certain minimum threshold, then the user can beinformed that the tissue where the A2 amplitude was obtained has beenproperly ablated. For example, in some embodiments, adequate ablation ortreatment can be confirmed when the A1/A2 ratio is greater than 1.5(e.g., 1.5-1.6, 1.6-1.7, 1.7-1.8, 1.8-1.9, 1.9-2.0, 2.0-2.5, 2.5-3.0,values between the foregoing, greater than 3, etc.). However, in otherembodiments, confirmation of ablation can be obtained when the ratio ofA1/A2 is less than 1.5 (e.g., 1-1.1, 1.1-1.2, 1.2-1.3, 1.3-1.4, 1.4-1.5,values between the foregoing, etc.).

FIG. 9 illustrates one embodiment of an expandable system 500 comprisinga plurality of mapping electrodes 520. Such systems 500 can include oneor more expandable members (e.g., struts, balloons, etc.) 510 thatsupport the electrodes 520 and help place such electrodes in contact orotherwise in close proximity to a subject tissue. For example, thedepicted embodiment of a mapping system 500 comprises a generallyspherical configuration when expanded. In some embodiments, such asystem 500 is sized, shaped and/or otherwise configured to be positionedand expanded within a heart chamber (e.g., atrium, ventricle) of asubject. In some arrangements, the struts comprise sufficientresiliency, stability, flexibility and/or other properties to enable theexpanded system 500 to conform or generally conform to the bodily cavityor other space (e.g., atrium) in which it is positioned. Although onerepresentation of a commercially-available system is depicted in FIG. 9,such systems with mapping electrodes can include any other shape, sizeand/or configuration, depending on one or more factors and/or otherconsiderations, such as, for example, the targeted tissue of thesubject, the number of electrodes that are desired or necessary and/orthe like. For example, in other embodiments, such systems can includemore or fewer electrodes, a non-spherical shape (e.g., conical,cylindrical, irregular, etc.) and/or the like, as desired or requiredfor a particular application or use.

Regardless of the exact design, configuration and/or other properties ofa commercially-available mapping system that may be utilized, theelectrodes included within the mapping system can vary, as desired orrequired. For example, in some embodiments, the electrodes 520 compriseunipolar or bipolar electrodes. In addition, the shape, size,configuration and/or other details of the electrodes 520 used in suchsystems 500 may vary, based on the specific system design.

According to some embodiments, such mapping systems 500 are utilized tohelp map a subject's cardiac chamber (e.g., atrium) during a cardiacfibrillation (e.g., atrial fibrillation) treatment. For example, in someinstances, subjects that indicate for atrial fibrillation exhibit anatrial fibrillation rotor pattern in their atrium that is characteristicof the disease. In some arrangements, electrically mapping the signalsbeing transmitted through a subject's atrium, and thus, more accuratelydetermining a map of the corresponding atrial fibrillation rotor that iscause of the disease, can assist with the subject treatment of thesubject. For example, in some embodiments, once the atrial fibrillationrotor is accurately mapped, a practitioner can more precisely treat theportions of the atrium that help treat the disease. This can provideseveral benefits to a subject, including more precise and accurateablation that increases the likelihood of effective treatment, lesstrauma to the subject as area or volume of tissue that is ablated can bereduced and/or the like.

In some embodiments, however, commercially-available mapping systems500, such as the one schematically illustrated in FIG. 9, have certainshortcomings. For example, depending on how the system is positionedwithin the targeted anatomical area and/or how the system is deployed,one or more regions of the targeted anatomical volume, space or otherregion may not be close to a mapping electrode 520. For example, in someembodiments, the splines or other expandable members 510 of a system arenot evenly deployed. In other instances, such expandable members 510,for one or more reasons, may not even expand properly or may not expandas intended or expected. As a result, in some cases, mapping electrodes520 do not properly contact the targeted tissue and/or may leaverelatively large areas of tissue between them. Accordingly, under suchcircumstances, the ability of such systems 500 to accurately map atargeted region of the subject's anatomy may be negatively impacted.

Therefore, according to some embodiments, a high-resolution-tipelectrode catheter system, identical or similar to the systems anddevices disclosed herein, can be used as a roving or gap-filling systemto create a more accurate and complete electrical map of the targetedanatomical area. Thus, in some embodiments, the system and relatedmethods disclosed herein do not rely solely on the various electrodes ofa multi-electrode system or device in order to obtain a map (e.g.,three-dimensional map) of tissue being mapped (e.g., cardiac tissue). Byway of example, as illustrated schematically in FIG. 10, one or moregaps between the mapping electrodes 520 of a separate mapping system 500can be “filled” or otherwise addressed from a mapping perspective usingthe high-resolution capabilities of the high-resolution-tip design.Accordingly, as schematically illustrated in FIG. 10, ahigh-resolution-tip electrode system can be directed to locations 530where additional mapping data are required or desired.

In some arrangements, a catheter in accordance with any of thehigh-resolution-tip embodiments disclosed herein (e.g., thoseillustrated and discussed herein with reference to FIGS. 1 to 7) can bemanually or positioned in some intermediate regions (e.g., regions wherea mapping system's electrodes were unable to reach or cover). Thus, byusing the high-resolution-tip electrode system as a roving mappingsystem, more accurate and comprehensive electrical mapping can beaccomplished. As a result, in some embodiments, such a roving system(e.g., a catheter comprising a high-resolution electrode) is adapted toobtain mapping data for intermediate tissue locations (e.g., tissuelocations located between electrodes of an expandable mapping system orother multi-electrode system or device). As noted above, this can resultin a more complete and accurate understanding of the subject's diseaseand how to more efficiently, safely and effectively treat it. Relatedly,the number of individual ablations (and thus, the total area or volumeof tissue that will be ablated) can be advantageously reduced, therebyreducing the overall trauma to the subject, reducing and otherwisemitigating the likelihood of any negative side effects from a treatmentprocedure, reducing recovery time and/or providing one or moreadditional advantages or benefits.

FIG. 11 illustrates a schematic of a mapping system 600 configured toobtain tissue mapping data using at least two different devices. Forexample, in the illustrated embodiment, the system 600 comprises a firstdevice or system (S1) 20 and a second system (S2) 500. According to someembodiments, the first system 20 includes a roving catheter (e.g.,comprising a high-resolution-tip design) in accordance with the variousconfigurations disclosed herein or variations thereof. Further, in someembodiments, the second device or system (S2) 500 comprises a pluralityof mapping electrodes (e.g., an expandable, catheter-based mappingsystem that includes electrodes along different splines and/or otherexpandable members).

With continued reference to the schematic of FIG. 11, depending on thetype of electrode(s) that are included in each of the first and seconddevices or systems 20, 500, the mapping system 600 can include one ormore reference electrodes 50, 550. For example, such referenceelectrodes may be necessary to obtain the necessary mapping data if theelectrodes are unipolar. Therefore, in some embodiments, referenceelectrodes are unnecessary and thus optional and/or not included. By wayof example, reference electrodes 50, 550 may be unnecessary if the firstand/or the second devices or systems 20, 500 comprise bipolar electrodes(e.g., having a high-resolution-tip design). As discussed herein, insome embodiments, second device or system 500 can include amulti-electrode design that is configured to obtain a plurality ofmapping data points at once. For example, second system 500 can includeone or more expandable members (e.g., splines, struts, balloons, otherinflatable members, other mechanically expandable members or features,etc.). In some embodiments, each such expandable member can include oneor more electrodes (e.g., unipolar, bipolar, etc.) that are configuredto contact a certain region of the targeted anatomical region (e.g.,atrium, ventricle, etc.) upon expansion of the second system 500. Thus,the various electrodes included in the second system 500 can be used tosimultaneously obtain several different mapping data points within thetargeted anatomical structure of a subject.

However, as noted herein, it may be desirable and beneficial to obtainadditional mapping data at locations of the targeted anatomicalstructure that are between the specially-preset or predeterminedlocations associated with each of the electrodes of the second device orsystem 500. In some instances, the second device or system 500 may notbe able to cover the entire desired extent or surface coverage or borderof the targeted anatomical structure due to anatomical constraints orsize or other physical, structural or operational constraints of thesecond system 500, thereby preventing a complete mapping of the targetedanatomical structure using the second system 500 alone. Accordingly, insome embodiments, a roving system, such as, for example, a cathetercomprising a high-resolution-tip design (e.g., such as the variouscatheter systems disclosed herein) can be used to obtain suchintermediate or additional mapping data. The roving system may also beused to determine anatomic region or tissue borders (e.g., superior venacava border and pulmonary vein tissue borders).

With continued reference to the schematic of FIG. 11, the first deviceor system 20 (e.g., a catheter-based high-resolution-tip system, anothertype of roving mapping system, etc.) can be operatively coupled to afirst data acquisition device or subsystem 610. Likewise, the seconddevice or system 500 (e.g., multi-electrode mapping system) can beoperatively coupled to another data acquisition device or subsystem 612.As illustrated schematically in FIG. 11, each of the data acquisitiondevices or subsystems 610, 612 can be placed in data communicationand/or otherwise operatively coupled to a processor or other controlmodule 650. In some embodiments, the mapping system 600 furthercomprises an output device 670 (e.g., monitor, other display, acomputing device, etc.) that is operatively coupled to the processor 650and is configured to provide mapping data and/or other information tothe user. For example, such an output device 670 can include a graphicaland/or numerical representation of the mapping data 672 obtained by thefirst and second devices or systems 20, 500. The output device 670 canadditionally provide cardiac signal data (e.g., ECG) and/or the like, asdesired or required. In some embodiments, the output device 670 canfurther include a user input component (e.g., a keypad, keyboard,touchscreen, etc.) to permit the user to enter instructions,information, data and/or the like. Such a user input component 674 canbe integrated into the output device 670, as would be the case if theoutput device 670 included a touchscreen. However, in other embodiments,the system 600 comprises a separate user input device that isoperatively coupled to the processor 650, the output device 670 and/orany other component of the system 600, as desired or required.

In some embodiments, regardless of the exact configuration of anenhanced mapping system, such as the one illustrated in FIG. 11 anddescribed herein, the processor 650 of such a system 600 is adapted tocombine mapping data from a multi-electrode mapping system with datafrom a roving system (e.g., a catheter having a high-resolution-tipelectrode and/or another electrode design capable of mapping). Thecombined mapping data obtained by the two mapping devices or systems 20,500 can be advantageously combined within the processor 650 to providean enhanced (e.g., more accurate, more complete) 3D map. As discussed ingreater detail herein (e.g., with reference to FIG. 14), the processor650 of the system 600 can be adapted to “align” the data from the twodifferent mapping devices or systems 20, 500 as part of creating theenhanced three-dimensional (3D) map.

As discussed above, the multi-electrode mapping device or system 500and/or the roving device or system 20 can include one or more bipolarmapping electrodes (e.g., high-resolution-tip electrodes). Thus, in suchconfigurations, the electrodes can be used to obtain mapping datawithout the use of a reference electrode. However, in some embodiments,the multi-electrode mapping device or system 500 and/or the rovingdevice or system 20 can include one or more unipolar mapping electrodes.In such arrangements, the need exists for one or more referenceelectrodes in order to obtain the desired mapping data for thoseunipolar electrodes. Thus, in some embodiments, the mapping system 600can include one or more reference electrodes. Such reference electrodescan be located external to the subject (e.g., an electrode secured tothe subject's skin, such as, for example, a right leg electrode) and/orinternal to the subject (e.g., within the subject's superior or inferiorvena cava or other vessel), as desired or required.

FIG. 12 schematically illustrates one embodiment of an enhanced mappingsystem 600 that includes a mapping device or system 500 having aplurality of mapping electrodes and a roving device or system 20 (e.g.,a catheter with a high-resolution-tip electrode configuration, acatheter with another type of unipolar or bipolar electrode for mapping,etc.). As schematically depicted in FIG. 11, each of the mapping devicesor systems 20, 500 can be operatively coupled to a processor or controlunit 650 that is configured to retrieve the mapping data obtained byeach of the systems or devices 20, 500 and generate an enhanced 3D mapor other output of the targeted anatomical region being mapped. In FIG.12, the additional data points obtained by the roving mapping device orsystem (e.g., the catheter with a high-resolution-tip design) areillustrated as dots or points between the set electrode locations of themulti-electrode system or device 500. Thus, as noted in greater detailherein, a user can obtain additional mapping data points to create amore accurate and complete 3D map of the targeted anatomical regionbeing mapped (e.g., the atrium, the ventricle, another region within ornear the heart, another anatomical region altogether, etc.).

FIG. 13 illustrates one embodiment of an algorithm used by an enhancedmapping system (e.g., such as the configurations disclosed herein,including, without limitation, the system 600 of FIGS. 11 and 12) tocreate an enhanced 3D map of a targeted anatomical region being mapped.As depicted in FIG. 13, in some embodiments, data is collected (block710) from a multi-electrode device or system (e.g., the multi-electrodemapping device or system 500 of FIGS. 11 and 12). Further, the mappingsystem can collect data (block 714) from a high resolution catheter orother device or system (e.g., such as a catheter having ahigh-resolution-tip electrode or other high-resolution electrodedesign). In some embodiments, the data obtained from each of the mappingsystems or devices 20, 500 is aligned or synchronized (block 718) by thesystem. Such a step can help normalize the mapping data so that themapping data accurately reflect the state of the various tissuelocations being mapped.

With continued reference to FIG. 13, the system can generate (block 722)an enhanced 3D map of the anatomical region being mapped. At block 726,such mapping data can optionally be provided to a display in order tovisually or graphically provide information to the user regarding thetissue being mapped. Alternatively, the mapping data can be saved on astorage device for future processing and review. In some embodiments,the display is integrated with the system. Alternatively, however, thesystem can be configured to operatively couple to a separate displaythat is not provided or included with the system.

According to some embodiments, a mapping system can include one or moreof the following components: a high-resolution mapping catheter (e.g., aroving catheter), a device having a plurality of mapping electrodes(e.g., configured to produce unipolar and/or bipolar signals), agenerator or other energy delivery module, a processor (e.g., which canbe included within a generator or other energy delivery module, anothercomponent of the system, etc.), a display for displaying mapping data(e.g., in the form of an enhanced three-dimensional map), a user inputdevice and/or any other component. For example, in some embodiments, thesystem comprises only a generator, other energy delivery module and/orother component comprising a processor that is configured to receivedata from two or more mapping devices (e.g., a multi-electrode device, aroving catheter device, etc.). In such embodiments, the processor canreceive mapping data from each device and create an enhancedthree-dimensional map of the targeted tissue.

In other embodiments, the mapping system comprises only high resolutionmapping catheter that is configured to be used with a separatemulti-electrode device. As discussed in greater detail herein, mappingdata obtained using such a high resolution catheter can be provided to aprocessor. Such a processor can also be configured to receiving mappingdata from a separate mapping system (e.g., a multi-electrode mappingsystem), and combine the mapping data from the two systems to create anenhanced three-dimensional map of the targeted area. In someembodiments, although it may not be provided with the system, theprocessor can be included as part of the high-resolution catheter or themulti-electrode mapping device or other separate mapping device. In yetother embodiments, the processor can be included as a stand-alone deviceor component that is not provided with either the mapping catheter orthe multi-electrode (or other) mapping device. Thus, in sucharrangements, a separate processor (e.g., positioned within a device)can be used to connect two different mapping systems. Such a processorcan be configured to operatively couple to two or more different mappingdevices and/or systems (e.g., via wired, wireless and/or otherconnections). The processor can receive mapping data from each of themapping devices and/or systems and to generate an enhanced threedimensional map.

According to some embodiments, a mapping system comprises one or more ofthe following devices and/or components: a high resolution catheter, anexpandable device including a plurality of mapping electrodes, separatedata acquisition devices configured to receive data from thehigh-resolution catheter and a multi-electrode mapping device (e.g.,expandable device with mapping electrodes), a data acquisition deviceconfigured to receive data from both the multi-electrode mapping deviceand a multi-electrode mapping device, a processor configured to receivethe mapping data from one or more data acquisition devices and toprocess said data to create an enhanced map (e.g., a three-dimensionalmap of the targeted tissue), an integrated data acquisition device andprocessor configured to receive mapping data from both thehigh-resolution catheter and mapping electrodes from a separateexpandable device and to process said data to create an enhanced map(e.g., a three-dimensional map of the targeted tissue), a display orother output configured to visually display data and/or graphics relatedto a map (e.g., a three-dimensional map) of the mapping data obtainedand processed by the mapping system and/or one or more other components,devices and/or systems, as desired or required.

By way of example, in one embodiment, the mapping system comprises ahigh resolution catheter, an expandable device comprising a plurality ofmapping electrodes, a data acquisition device configured to receivemapping data from both the high-resolution catheter and the mappingelectrodes of expandable mapping device. In such configurations, thesystem can further include a processor configured to receive the mappingdata from the data acquisition device and to process such (e.g., alignthe data) to generate an enhanced map (e.g., a three-dimensional map) ofthe tissue. In some embodiments, the system comprises (or is otherwiseconfigured to operatively couple, e.g., via a wired or wirelessconnection) to a display or other output device.

In accordance with the specific embodiment described above, mapping dataare acquired from various mapping electrodes of an expandable system(e.g., a basket) and from a roving catheter having a high-resolutionelectrode. The catheter can be selectively moved within one or more gapslocated between the electrodes of the expandable system to create a morecomplete and comprehensive map. The mapping data from the two differentdevices can be acquired by a single device, component and/or system(e.g., a device or component associated with or part of thehigh-resolution electrode catheter, a device or component associatedwith or part of the multi-electrode device, etc.). Further, as describedin at least some of embodiments disclosed herein, a separate processor(e.g., processor 650) can be used to obtain the mapping data of thehigh-resolution catheter and the mapping electrodes of an expandablesystem. Such a processor can receive the mapping data and integrate them(e.g., align them) in order to be able to produce an enhancedthree-dimensional map of the targeted tissue.

In other embodiments, the same device, component and/or system thatacquires the mapping data from the two different devices is alsoconfigured to process such data and create an enhanced map (e.g., athree-dimensional map) of the targeted tissue. Such a single dataacquisition device and processor can be part of the expandable system,the system that comprises the high-resolution catheter or a separatedeice, component and/or a separate system altogether, as desired orrequired.

In yet other embodiments, each of the high-resolution catheter deviceand a multi-electrode mapping device comprises a separate dataacquisition device (e.g., the system does not include a single dataacquisition device that is configured to receive mapping data from twoseparate devices). In such embodiments, the data acquired from each ofthe data acquisition devices can be provided to a separate processor toprocess the data (e.g. integrate the data) and to produce an enhancedmap (e.g., a three-dimensional map) of the tissue being mapped.

As represented graphically in FIG. 14 and discussed in greater detailherein, the processor (e.g., processor 650) of an enhanced mappingsystem (e.g., one that uses two different mapping devices or systems)may need to align or otherwise manipulate the data obtained by each ofthe mapping systems operatively coupled to the system. For example, insome embodiments, the data are aligned or synchronized by applying anadjustment associated with the R-waves of the various electrocardiograms810, 820 generated by each of the mapping devices or systems.Alternatively, other cardiac fiducial points may be used, includingthose coming for other sensor types, such as cardiac pressure sensors.As illustrated in FIG. 14, for example, the—waves can be aligned (e.g.,graphically represented by dashed lines 830) in the correspondingelectrocardiograms 810, 820 in order for the data obtained by the twodevices or systems to be adjusted, and for a corresponding 3D map thatintegrates the data to be accurate.

According to some embodiments, as and/or after an enhanced 3D map of thetargeted anatomical region is obtained, the first device or system(e.g., the catheter with the high-resolution-tip electrode or anothertype of electrode or energy delivery member) can be used to selectivelyablate certain portions of the tissue. For example, as discussed ingreater detail herein with reference to FIGS. 15A and 15B, a rovingcatheter-based system can be used to accurately detect any rotors (e.g.,that may be the result of atrial fibrillation or of other cardiaccondition) or other features or conditions within a targeted region(e.g., atrium) of a subject and ablate one or more portions of the saidregion (e.g., to interrupt the rotors). In some embodiments, the firstdevice or system can be used to confirm lesion maturation.

FIG. 15A illustrates one embodiment of a 3D tissue map 900 a obtainedusing only a multi-electrode system. In the illustrated arrangement, themulti-electrode device or system comprises a total of 64 electrodesthat, when expanded within a targeted anatomical structure of a subject(e.g., an atrium), are configured to contact, and thus obtain mappingdata, along specific locations of such a targeted anatomical structure.However, in other embodiments, a multi-electrode device or system caninclude fewer or greater than 64 electrodes, as desired or required. Asshown, the 3D rotor map is created using activation timing data (e.g.,as illustrated in FIG. 15A). Other types of cardiac maps can be createdas well, such as: cardiac activation maps, propagation velocity maps,voltage maps, etc.

As illustrated in the example 3D activation map of FIG. 15A, there existrelatively large gaps or spaces between adjacent electrodes of themulti-electrode device or system. As a result, the corresponding 3D mapthat is generated using only the multi-electrode mapping device orsystem may be inaccurate and/or incomplete. For example, in someembodiments, there may exist a rotor or other indicia of a cardiacarrhythmia (e.g., atrial fibrillation) or other condition that may notbe identified by the fixed-space electrodes of a multi-electrode mappingdevice or system.

By way of example, FIG. 15B illustrates a region 920 of the subject'sanatomical space that has been mapped using a roving (e.g.,catheter-based) device or system, in accordance with the variousembodiments disclosed herein. Thus, when contrasted to the 3D map ofFIG. 15A, the map of FIG. 15B provides additional mapping data betweenthe set, fixed locations of the electrodes in a multi-electrode deviceor system. For example, such additional information can be obtained in aregion 920 located generally between the various set point locations ofthe fixed electrodes 910 of the multi-electrode device or system. Insome embodiments, such intermediate mapping data can detect a differentrepresentation of the status of the corresponding tissue. For example,whereas in FIG. 15A, the tissue located at location 920 is not capableof being specifically mapped, a catheter having a high-resolution-tipelectrode (or some other embodiment of a roving mapping electrode) maybe able to obtain specific data regarding that intermediate location920. As a result, an intermediate region (e.g., having a relativelyearly activation) can be contrasted to data that was obtained by onlyusing the multi-electrode device or system (as shown in FIG. 15A).Consequently, the enhanced mapping system could be used to detect thepresence of a rotor 930 (e.g., wherein a region of the targetedanatomical region exhibits a localized area in which activation of saidtissue forms a circular or repetitive pattern). Thus, the presence of acondition can be accurately identified, and subsequently treated, usingembodiments of the enhanced mapping devices or systems disclosed herein.As enumerated above, the embodiments disclosed herein can be used togenerate many types of enhanced cardiac maps, such as, withoutlimitation: cardiac activation maps, cardiac activity propagationvelocity maps, cardiac voltage maps and rotor maps. In accordance withseveral embodiments, the enhanced mapping system facilitates morefocused, localized or concentrated ablation targets and/or may reducethe number of ablations required to treat various conditions.

FIG. 16 schematically illustrates a different embodiment 1000 afiltering element 1004 configured for use with any of the mappingdevices and systems disclosed herein (e.g., a roving catheter systemcomprising a high-resolution tip). The schematically depictedarrangement comprises a filter circuit 1004 that permits for thesimultaneous application of RF energy (e.g., during the application ofenergy to targeted tissue to heat or otherwise ablate such tissue) andmeasurement of EGM recordings (e.g., for high-resolution mapping). Thus,in some embodiments, a capacitor that is placed across two electrodes orelectrode portions can be replaced by a filter circuit such as the oneschematically depicted in FIG. 16. Any other type of filtering elementthat permits an electrode to deliver energy (e.g., RF energy) and toobtain high-resolution mapping data can be included in any of theembodiments disclosed herein or variations thereof.

With continued reference to FIG. 16, the filtering element 1004 caninclude a LC circuit. In some embodiments, such a LC circuit can betuned and otherwise configured to resonate near the RF energy frequency(e.g. 460 kHz, 400-500 kHz, 440-480 kHz, frequencies between theforegoing values, etc.), such that the electrodes or electrode portionsof a high-resolution catheter or other medical instrument or device 20have a relatively low impedance between them at the RF energy frequency.The impedance of the filter circuit increases dramatically at lowerfrequencies, such as the frequencies utilized for EGM recordings, thusallowing for the two electrodes to be disconnected from each other toallow an EGM signal to formulate across them. As shown in thearrangement of FIG. 16, the filtering element 1004 can include an EGMrecorder 1010 that is operatively coupled to a filter 1012. In addition,the RF generator or other energy delivery module, RF can be operativelycoupled to a RF return pad or similar member 1050.

According to some embodiments, in order to achieve a circuit thatresonates near a targeted frequency (e.g., 460 kHz) and that provides ahigh impedance at EGM frequencies, inductor values of 0.7 uH to 1000 uHmay be used. In some embodiments, the value of the capacitance can be0.12 to 170 nF. In some configurations, the LC circuit of such afiltering element 1004 is tuned to resonate at approximately 460 kHz(e.g. 460 kHz, 400-500 kHz, 440-480 kHz, frequencies between theforegoing values, etc.) by maintaining the relationship between L and Cvalues in accordance with eh following formula:

$C = \frac{1}{L \cdot ( {2 \cdot \pi \cdot f} )^{2}}$

In the formula provided above, C is the capacitance, L is theinductance, and f is the frequency. According to some embodiments, anominal value for the LC circuit may be L=20 uH and C=6 nF. However, inother configurations, such values can vary, as desired or required for aparticular application or design. One embodiment 1100 of impedancemagnitude versus frequency response of such LC circuits is graphicallyillustrated in FIG. 17. As noted herein, such a LC circuit oralternative filtering element can be used in any of the high-resolutionembodiments disclosed herein (e.g., in lieu of a capacitor or alteringfiltering element that permits for both the delivery of energy and theability to perform high-resolution mapping).

According to some embodiments, due to the nature of thehigh-resolution-tip electrode systems that are used to create a morecomplete and comprehensive map of targeted tissue, in accordance withthe various high-resolution-tip systems and devices disclosed herein,additional information regarding the position of the roving catheter(and thus, the intermediate mapping locations) can be obtained andprovided to the user during a procedure. For example, given thehigh-resolution mapping capabilities of such catheters, information canbe obtained regarding the nature, type and other details regarding thetissue that is adjacent the electrode. In addition, as noted above, thehigh-resolution-tip embodiments disclosed herein can help determinewhether a specific tissue region has been adequately ablated (e.g., seethe disclosure above with reference to FIG. 8).

In some embodiments, any of the high-resolution-tip electrode devices orsystems disclosed herein can be used as stand-alone mapping systems toaccurately assess the condition of a subject's targeted anatomicalregion, even with the use of a separate mapping system (e.g., such asthe one schematically illustrated in FIG. 9). For example, a user canmove a high-resolution-tip electrode catheter or other medicalinstrument to various locations within a subject's anatomy to generate adetailed, accurate and complete electrical map, as desired or required.

As a result of the high-resolution mapping capabilities of the varioushigh-resolution-tip electrode catheter devices and systems disclosedherein, an accurate map of the subject's targeted anatomical space orother region can be obtained. In addition, in view of the fact that suchsystems are also configured to advantageously ablate tissue, a moreefficient and accurate treatment procedure can be attained. For example,in embodiments where one of the high-resolution-tip electrodes devicesor systems disclosed herein is being use to map a subject's anatomy(e.g., atrium), either with or without the use of a separate (e.g.,commercially-available mapping system), such a high-resolution-tipdevice or system can be used to also ablate tissue. This can facilitateand improve the execution of a treatment procedure. For example, theability to use a single device to both map and ablate tissue permits auser to more expeditiously perform an overall assessment and treatmentof a subject. In addition, the ability to create a more comprehensivemap of the subject's tissue, allows a user to perform a subjecttreatment procedure with greater accuracy and precision. As discussed,this can help reduce the overall (and sometimes unnecessary) trauma tothe subject, improve recovery and provide for better and effectivetreatment of the subject's disease. In addition, as noted above, theability of the user to determine whether tissue has already been ablatedor otherwise treated to a sufficient level can further improve theefficacy, efficiency and/or safety of a procedure.

In some embodiments, the system comprises various features that arepresent as single features (as opposed to multiple features). Forexample, in one embodiment, the system includes a single roving catheterthat is configured to obtain high-resolution mapping of tissue and asingle separate mapping device or system that includes mappingelectrodes for mapping tissue of the subject. The separate mappingdevice or system can include an at least one expandable member, whereinat least some of the plurality of mapping electrodes of the separatemapping device or system are positioned along the expandable member. Theroving catheter is configured to obtain mapping data in tissue regionsnot adequately covered by the separate mapping device or system. Thesystem can include a single data acquisition device for receivingmapping data from the roving catheter and/or the separate mapping deviceor system. The system can further include a single processor that isconfigured to generate a three-dimensional map using the mapping datareceived by the data acquisition device. Thus, in some embodiments, thesystem does not require separate processors to receive and processmapping data that are received from separate mapping devices or systems(e.g., a multi-electrode mapping system or device, a roving catheterhaving a high-resolution electrode, etc.). The roving catheter caninclude a split-tip electrode design and/or any other high-resolutionconfiguration. The processor can be configured to selectively ablatetissue based on the mapping data obtained from the roving catheter andthe separate mapping device or system.

According to some embodiments, the system consists essentially of aroving catheter that is configured to obtain high-resolution mapping oftissue, a separate mapping device or system that includes mappingelectrodes for mapping tissue of the subject and a data acquisitiondevice for receiving mapping data from the roving catheter and/or theseparate mapping device or system. In some embodiments, the systemconsists essentially of roving catheter that is configured to obtainhigh-resolution mapping of tissue, a separate mapping device or systemthat includes mapping electrodes for mapping tissue of the subject, adata acquisition device for receiving mapping data from the rovingcatheter and/or the separate mapping device or system and a processorthat is configured to generate a three-dimensional map using the mappingdata received by the data acquisition device.

In some embodiments, the system comprises various features that arepresent as single features (as opposed to multiple features). Forexample, in one embodiment, the system includes a single ablationcatheter with a single energy delivery radiofrequency electrode and oneor more temperature sensors (e.g., thermocouples) to help determine thetemperature of tissue at a depth. The system may comprise an impedancetransformation network. Multiple features or components are provided inalternate embodiments.

In some embodiments, the system comprises one or more of the following:means for tissue modulation (e.g., an ablation or other type ofmodulation catheter or delivery device), means for generating energy(e.g., a generator or other energy delivery module), means forconnecting the means for generating energy to the means for tissuemodulation (e.g., an interface or input/output connector or othercoupling member), means for obtaining mapping data using amulti-electrode mapping system (e.g., an expandable system that engagesvarious portions of targeted tissue), means for obtaining mapping data(e.g., high-resolution data) in areas of the tissue located between theelectrodes of a multi-electrode mapping system, means for acquiring data(e.g., using one or more data acquisition devices) from themulti-electrode mapping device or system and/or a device comprising ahigh-resolution electrode assembly (e.g., a roving catheter), means forprocessing mapping data obtained from the means for acquiring data(e.g., using a processor) to, e.g., generate a three-dimensional map,etc.

Any methods described herein may be embodied in, and partially or fullyautomated via, software code modules executed by one or more processorsor other computing devices. The methods may be executed on the computingdevices in response to execution of software instructions or otherexecutable code read from a tangible computer readable medium. Atangible computer readable medium is a data storage device that canstore data that is readable by a computer system. Examples of computerreadable mediums include read-only memory, random-access memory, othervolatile or non-volatile memory devices, CD-ROMs, magnetic tape, flashdrives, and optical data storage devices.

In addition, embodiments may be implemented as computer-executableinstructions stored in one or more tangible computer storage media. Aswill be appreciated by a person of ordinary skill in the art, suchcomputer-executable instructions stored in tangible computer storagemedia define specific functions to be performed by computer hardwaresuch as computer processors. In general, in such an implementation, thecomputer-executable instructions are loaded into memory accessible by atleast one computer processor. The at least one computer processor thenexecutes the instructions, causing computer hardware to perform thespecific functions defined by the computer-executable instructions. Aswill be appreciated by a person of ordinary skill in the art, computerexecution of computer-executable instructions is equivalent to theperformance of the same functions by electronic hardware that includeshardware circuits that are hardwired to perform the specific functions.As such, while embodiments illustrated herein are typically implementedas some combination of computer hardware and computer-executableinstructions, the embodiments illustrated herein could also beimplemented as one or more electronic circuits hardwired to perform thespecific functions illustrated herein.

The various systems, devices and/or related methods disclosed herein canbe used to at least partially ablate and/or otherwise ablate, heat orotherwise thermally treat one or more portions of a subject's anatomy,including without limitation, cardiac tissue (e.g., myocardium, atrialtissue, ventricular tissue, valves, etc.), a bodily lumen (e.g., vein,artery, airway, esophagus or other digestive tract lumen, urethra and/orother urinary tract vessels or lumens, other lumens, etc.), sphincters,other organs, tumors and/or other growths, nerve tissue and/or any otherportion of the anatomy. The selective ablation and/or other heating ofsuch anatomical locations can be used to treat one or more diseases orconditions, including, for example, atrial fibrillation, mitral valveregurgitation, other cardiac diseases, asthma, chronic obstructivepulmonary disease (COPD), other pulmonary or respiratory diseases,including benign or cancerous lung nodules, hypertension, heart failure,denervation, renal failure, obesity, diabetes, gastroesophageal refluxdisease (GERD), other gastroenterological disorders, other nerve-relateddisease, tumors or other growths, pain and/or any other disease,condition or ailment.

In any of the embodiments disclosed herein, one or more components,including a processor, computer-readable medium or other memory,controllers (for example, dials, switches, knobs, etc.), displays (forexample, temperature displays, timers, etc.) and/or the like areincorporated into and/or coupled with (for example, reversibly orirreversibly) one or more modules of the generator, the irrigationsystem (for example, irrigant pump, reservoir, etc.) and/or any otherportion of an ablation or other modulation system.

Although several embodiments and examples are disclosed herein, thepresent application extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses of theinventions and modifications and equivalents thereof. It is alsocontemplated that various combinations or subcombinations of thespecific features and aspects of the embodiments may be made and stillfall within the scope of the inventions. Accordingly, it should beunderstood that various features and aspects of the disclosedembodiments can be combine with or substituted for one another in orderto form varying modes of the disclosed inventions. Thus, it is intendedthat the scope of the present inventions herein disclosed should not belimited by the particular disclosed embodiments described above, butshould be determined only by a fair reading of the claims that follow.

While the embodiments disclosed herein are susceptible to variousmodifications, and alternative forms, specific examples thereof havebeen shown in the drawings and are herein described in detail. It shouldbe understood, however, that the inventions are not to be limited to theparticular forms or methods disclosed, but, to the contrary, theinventions are to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the various embodiments describedand the appended claims. Any methods disclosed herein need not beperformed in the order recited. The methods disclosed herein includecertain actions taken by a practitioner; however, they can also includeany third-party instruction of those actions, either expressly or byimplication. For example, actions such as “advancing a catheter” or“delivering energy to an ablation member” include “instructing advancinga catheter” or “instructing delivering energy to an ablation member,”respectively. The ranges disclosed herein also encompass any and alloverlap, sub-ranges, and combinations thereof. Language such as “up to,”“at least,” “greater than,” “less than,” “between,” and the likeincludes the number recited. Numbers preceded by a term such as “about”or “approximately” include the recited numbers. For example, “about 10mm” includes “10 mm.” Terms or phrases preceded by a term such as“substantially” include the recited term or phrase. For example,“substantially parallel” includes “parallel.”

What is claimed is:
 1. A device for obtaining mapping data for atargeted anatomical tissue of a subject, comprising: a mapping deviceincluding a plurality of mapping electrodes, the plurality of mappingelectrodes including at least a first electrode member and a secondelectrode member coupled with a filtering element, the filtering elementbeing configured to: allow the simultaneous application ofradiofrequency ablation energy from the first electrode member and thesecond electrode member at a first radiofrequency range; and allow thefirst electrode member and the second electrode member to operate asseparate electrodes to facilitate mapping at a second frequency rangedifferent than the first frequency range.
 2. The device of claim 1,wherein the mapping device comprises at least one expandable member,wherein at least one of the plurality of mapping electrodes arepositioned along the at least one expandable member.
 3. The device ofclaim 1, wherein the mapping data received from the mapping devicecomprises at least one from the group consisting of unipolar and bipolarsignals.
 4. The device of claim 1, further including a processorconfigured to generate a three-dimensional map at least in part from themapping data received the mapping device.
 5. The device of claim 4,wherein the processor is configured to couple to an output device fordisplaying a three-dimensional map.
 6. The device of claim 1, whereinthe filtering element is a capacitor.
 7. The device of claim 1, whereinthe filtering element is disposed adjacent to the plurality of mappingelectrodes.
 8. The device of claim 1, wherein the filtering element isseparate from the mapping device.
 9. A system for obtaining mapping datafor a targeted anatomical tissue of a subject, the system comprising: adata acquisition device configured to receive mapping data from amapping catheter; and a processor configured to receive mapping datafrom the data acquisition device and from a separate mapping system,wherein the separate mapping system is configured to operatively coupleto the processor, the separate mapping system comprising a plurality ofmapping electrodes, the plurality of mapping electrodes including atleast a first electrode member and a second electrode member coupledwith a filtering element, the filtering element being configured to:allow the simultaneous application of radiofrequency ablation energyfrom the first electrode member and the second electrode member at afirst radiofrequency range; and allow the first electrode member and thesecond electrode member to operate as separate electrodes to facilitatemapping at a second frequency range different than the first frequencyrange.
 10. The system of claim 9, wherein the system is configured tooperatively couple to an output device for displaying saidthree-dimensional map.
 11. The system of claim 9, wherein the mappingcatheter includes a tip electrode.
 12. The system of claim 9, whereinthe separate mapping system comprises at least one expandable member,the at least one expandable member comprising at least one of theplurality of mapping electrodes.
 13. The system of claim 12, wherein theseparate mapping system comprises an expandable basket.
 14. The systemof claim 9, wherein the processor is configured to align or synchronizedata obtained from the mapping catheter and from the separate mappingsystem.
 15. The system of claim 9 wherein the processor is separate fromthe data acquisition device.